IN THE MOVIE “Selena,” about the slain Tejano singer, there is a priceless scene where Edward James Olmos tries to explain how difficult it is to be Mexican American. One has to be more Mexican than Mexicans, he says, and more American than Americans.

“We’ve got to know about John Wayne and Pedro Infante … Oprah and Cristina,” he says. “It’s exhausting.”

That scene came to mind when I saw that goofy photo of Barack Obama in traditional Somali dress, complete with turban, during a visit to Africa — the photo that Hillary Clinton assures us did not come from anyone in her campaign “so far as I know.”

It’s pretty clear why the photo, which had already appeared in a supermarket tabloid, enjoyed a second life on the Internet: It is part of an effort by Obama’s critics to portray him — and, his wife, Michelle — as unpatriotic, ungrateful and un-American.

Apparently, to those with prejudices, depicting someone as a foreigner, or even dressed in foreign garb, gets you halfway there. In Obama’s case, it only adds fuel to the furor that he chooses not to wear a flag pin on his lapel.

This exercise is familiar territory for Mexican Americans, condemned to spend eternity trying to convince skeptical countrymen that they bleed red, white and blue and can recite the lyrics to “America the Beautiful” — in English. For the most part, what the skeptics want is a guarantee that, in the unlikely event that war breaks out with Mexico, Mexican Americans would come down on the right side of the hyphen.

How idiotic. Mexican Americans are the last people on Earth who owe anything to Mexico, which disowned their ancestors. Everything they have achieved they owe to the blessing of living in the United States.

In recent days, Barack and Michelle Obama have been saying much the same thing. They insist that one doesn’t run for president unless one feels an undying love for one’s country.

Michelle Obama never said she didn’t love her country. What she said to an audience in Milwaukee was that “for the first time in my adult life, I am really proud of my country. Not just because Barack is doing well, but (because) I think people are hungry for change.”

Conservative commentators — including some white men who don’t have a clue what it is like to walk in Michelle Obama’s shoes — couldn’t wait to pounce on the remarks, as if their suspicions had been confirmed. Suddenly, the graduate of Princeton University and Harvard Law School was transformed into the female equivalent of Eldridge Cleaver.

But what gives the commentators the right to lecture someone else — let alone someone with a different life experience — about how she should feel about her country? Few things are more personal.

Later, Michelle said that what she meant to say was simply that she was proud that Americans were excited about the political process. Asked if she had always been proud of her country, Michelle replied “absolutely” and noted that she and her husband both have been given many opportunities for which they are grateful.

The irony is that those very opportunities — such as the chance to attend elite universities — may make it more difficult for the Obamas and others with similar credentials to identify with their fellow African Americans even as they’re viewed suspiciously by the mainstream. It can be a lonely place.

That was the conclusion of a Princeton senior who, in her senior thesis, examined whether black alumni of the university were, as a result of their time at Princeton, “more or less motivated to benefit the black community.” After interviewing 89 black graduates, the student suggested that attending the school decreased the extent to which black alumni identified with the larger African-American community.

The student also drew on her own experience, which, she wrote, was consistent with that of the black alumni. Her name was Michelle LaVaughn Robinson, but today she is Michelle Obama.

Her thesis is not exactly “Soul on Ice,” but it does provide a glimpse into world of the African-American high achiever. You spend your life studying and working hard and, for your trouble, you find yourself alienated from the rest of your community. Then, years later, something happens to convince you that neither are you accepted by some in the larger community. So you expend a lot of effort trying to fit into both.